In a mixing bowl, combine gluten-free flour, butter, sugar, egg, matcha powder, and salt. Mix until a dough forms.

Wrap the dough in plastic wrap and refrigerate for 30 minutes.

Preheat the oven to 350°F (175°C).

Roll out the dough on a floured surface and cut into rectangles.

Place a spoonful of jam in the center of half the rectangles, then top with the remaining rectangles.

Seal the edges with a fork and place on a baking sheet.

Bake in the preheated oven for 20 minutes or until golden brown.

While baking, mix powdered sugar, milk, and matcha powder to create the glaze.

Once the pop tarts are cool, drizzle the glaze over them.